COVID-19 long-term sequelae: Omicron versus Alpha and Delta variants

Abstract:

Background: The study aimed to assess the association between three predominant SARS-CoV-2 variants (Alpha, Delta, and Omicron) and the risk of developing long COVID (persistence of physical, medical, and cognitive symptoms more than 4 weeks after infection), post-COVID-19 syndrome (symptoms extending beyond 12 weeks), and viral persistence (testing positive beyond 4 weeks despite clinical resolution).

Methods: Retrospective study of 325 patients hospitalized for COVID-19 with genomic sequencing information. For each SARS-CoV-2 variant, sample characteristics, frequency of symptoms, and long-term sequelae were compared using Chi-squared test, Fisher’s exact test, Kruskal-Wallis test, and Dunn’s test as appropriate. Odds ratios (OR) were calculated using logistic regression models to assess the association of risk factors and sequelae.

Results: The adjusted model showed that the Omicron (vs Alpha) variant (OR, 0.30; 95% CI0.16-0.56), admission to ICU (OR, 1.14; 95% CI 1.05-1.23), and being treated with antiviral or immunomodulatory drugs (OR, 2.01; 95% CI 1.23-3.27) predicted long COVID and post-COVID-19 syndrome. Viral persistence showed no difference between variants.

Conclusions: The Omicron variant was associated with significantly lower odds of developing long-term sequelae from COVID-19 compared with previous variants, while severity of illness indicators increased the risk. Vaccination status, age, sex, and comorbidities were not found to predict sequelae development. This information has implications for both health managers and clinicians when deciding on the appropriate clinical management and subsequent outpatient follow-up of these patients. More studies with non-hospitalized patients are still necessary.

Source: Hernández-Aceituno A, García-Hernández A, Larumbe-Zabala E. COVID-19 long-term sequelae: Omicron versus Alpha and Delta variants. Infect Dis Now. 2023 Feb 27:104688. doi: 10.1016/j.idnow.2023.104688. Epub ahead of print. PMID: 36858287; PMCID: PMC9970656. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9970656/ (Full text)

Is exposure to Epstein-Barr virus a risk factor for long-covid?

Abstract:

Background: A viral etiology to chronic fatigue syndrome (CFS) has long been postulated, and Epstein-Barr Virus (EBV) was the first CFS associated virus. CFS and Long-COVID share features, potentially implicating a similar etiology. This study evaluated if EBV exposure is associated with post-COVID syndrome (Long-COVID)

Methods: Intermountain Healthcare electronic health records were queried to identify patients diagnosed with COVID-19 and tested for EBV between March 6, 2020 and April 13, 2022. A subsequent diagnosis of Long-COVID (ICD-10 U09.9) was evaluated using survival methods.

Results: Overall, 296,959 patients had COVID-19 and 590 had concurrent EBV test results [207 (35.1%) were EBV positive]. Subjects averaged 27.4±18.4 years of age (range: 0-86); 57.6% were female. Hospitalization occurred in 61 subjects (10.3%) within 30 days of COVID-19 diagnosis, with 17 (2.9%) requiring intensive care. Long-COVID was found in 29 (4.9%) subjects (just 10 were among the 61 hospitalized for COVID-19), with 15 (7.2%) EBV positive (Figure) and 14 (3.7%) EBV negative (HR=2.09, 95% CI=1.01, 4.34; p=0.042). EBV risk remained in multivariable analyses. Race, hyperlipidemia, and tobacco use also predicted Long-COVID, with histories of anticoagulant and vitamin D use were protective.

Conclusion: In a large prospectively-collected registry, EBV positivity was associated with an elevated risk of Long-COVID. This suggests that EBV may be a predisposing risk factor for or co-precipitant of Long-COVID.

Source: Horne B, Knowlton K, Le V, et al. IS EXPOSURE TO EPSTEIN-BARR VIRUS A RISK FACTOR FOR LONG-COVID?. J Am Coll Cardiol. 2023 Mar, 81 (8_Supplement) 1784. https://doi.org/10.1016/S0735-1097(23)02228-3 (Full text)

Effect of covid-19 vaccination on long covid: systematic review

Abstract:

Objective To determine the effect of covid-19 vaccination, given before and after acute infection with the SARS-CoV-2 virus, or after a diagnosis of long covid, on the rates and symptoms of long covid.

Design Systematic review.

Data sources PubMed, Embase, and Cochrane covid-19 trials, and Europe PubMed Central (Europe PMC) for preprints, from 1 January 2020 to 3 August 2022.

Eligibility criteria for selecting studies Trials, cohort studies, and case-control studies reporting on patients with long covid and symptoms of long covid, with vaccination before and after infection with the SARS-CoV-2 virus, or after a diagnosis of long covid. Risk of bias was assessed with the ROBINS-I tool.

Results 1645 articles were screened but no randomised controlled trials were found. 16 observational studies from five countries (USA, UK, France, Italy, and the Netherlands) were identified that reported on 614 392 patients. The most common symptoms of long covid that were studied were fatigue, cough, loss of sense of smell, shortness of breath, loss of taste, headache, muscle ache, difficulty sleeping, difficulty concentrating, worry or anxiety, and memory loss or confusion. 12 studies reported data on vaccination before infection with the SARS-CoV-2 virus, and 10 showed a significant reduction in the incidence of long covid: the odds ratio of developing long covid with one dose of vaccine ranged from 0.22 to 1.03; with two doses, odds ratios were 0.25-1; with three doses, 0.16; and with any dose, 0.48-1.01. Five studies reported on vaccination after infection, with odds ratios of 0.38-0.91. The high heterogeneity between studies precluded any meaningful meta-analysis. The studies failed to adjust for potential confounders, such as other protective behaviours and missing data, thus increasing the risk of bias and decreasing the certainty of evidence to low.

Conclusions Current studies suggest that covid-19 vaccines might have protective and therapeutic effects on long covid. More robust comparative observational studies and trials are needed, however, to clearly determine the effectiveness of vaccines in preventing and treating long covid.

Source: Byambasuren OStehlik PClark J, et al. Effect of covid-19 vaccination on long covid: systematic review

Efficacy of first dose of covid-19 vaccine versus no vaccination on symptoms of patients with long covid: target trial emulation based on ComPaRe e-cohort

Abstract:

Objective To evaluate the effect of covid-19 vaccination on the severity of symptoms in patients with long covid.

Design Target trial emulation based on ComPaRe e-cohort.

Data source ComPaRe long covid cohort, a nationwide e-cohort (ie, a cohort where recruitment and follow-up are performed online) of patients with long covid, in France.

Methods Adult patients (aged ≥18 years) enrolled in the ComPaRe cohort before 1 May 2021 were included in the study if they reported a confirmed or suspected SARS-CoV-2 infection, symptoms persistent for >3 weeks after onset, and at least one symptom attributable to long covid at baseline. Patients who received a first covid-19 vaccine injection were matched with an unvaccinated control group in a 1:1 ratio according to their propensity scores. Number of long covid symptoms, rate of complete remission of long covid, and proportion of patients reporting an unacceptable symptom state at 120 days were recorded.

Results 910 patients were included in the analyses (455 in the vaccinated group and 455 in the control group). By 120 days, vaccination had reduced the number of long covid symptoms (mean 13.0 (standard deviation 9.4) in the vaccinated group v 14.8 (9.8) in the control group; mean difference −1.8, 95% confidence interval −3.0 to −0.5) and doubled the rate of patients in remission (16.6% v 7.5%, hazard ratio 1.93, 95% confidence interval 1.18 to 3.14). Vaccination reduced the effect of long covid on patients’ lives (mean score on the impact tool 24.3 (standard deviation 16.7) v 27.6 (16.7); mean difference −3.3, 95% confidence interval −5.7 to −1.0) and the proportion of patients with an unacceptable symptom state (38.9% v 46.4%, risk difference −7.4%, 95% confidence interval −14.5% to −0.3%). In the vaccinated group, two (0.4%) patients reported serious adverse events requiring admission to hospital.

Conclusion In this study, covid-19 vaccination reduced the severity of symptoms and the effect of long covid on patients’ social, professional, and family lives at 120 days in those with persistent symptoms of infection.

Source: Tran VPerrodeau ESaldanha J, et al. Efficacy of first dose of covid-19 vaccine versus no vaccination on symptoms of patients with long covid: target trial emulation based on ComPaRe e-cohort.

Assessment of microbiota in the gut and upper respiratory tract associated with SARS-CoV-2 infection

Abstract:

Background: The human microbiome plays an important role in modulating the host metabolism and immune system. Connections and interactions have been found between the microbiome of the gut and oral pharynx in the context of SARS-CoV-2 and other viral infections; hence, to broaden our understanding of host-viral responses in general and to deepen our knowledge of COVID-19, we performed a large-scale, systematic evaluation of the effect of SARS-CoV-2 infection on human microbiota in patients with varying disease severity.

Results: We processed 521 samples from 203 COVID-19 patients with varying disease severity and 94 samples from 31 healthy donors, consisting of 213 pharyngeal swabs, 250 sputa, and 152 fecal samples, and obtained meta-transcriptomes as well as SARS-CoV-2 sequences from each sample. Detailed assessment of these samples revealed altered microbial composition and function in the upper respiratory tract (URT) and gut of COVID-19 patients, and these changes are significantly associated with disease severity. Moreover, URT and gut microbiota show different patterns of alteration, where gut microbiome seems to be more variable and in direct correlation with viral load; and microbial community in the upper respiratory tract renders a high risk of antibiotic resistance. Longitudinally, the microbial composition remains relatively stable during the study period.

Conclusions: Our study has revealed different trends and the relative sensitivity of microbiome in different body sites to SARS-CoV-2 infection. Furthermore, while the use of antibiotics is often essential for the prevention and treatment of secondary infections, our results indicate a need to evaluate potential antibiotic resistance in the management of COVID-19 patients in the ongoing pandemic. Moreover, a longitudinal follow-up to monitor the restoration of the microbiome could enhance our understanding of the long-term effects of COVID-19.

Source: Li J, Jing Q, Li J, Hua M, Di L, Song C, Huang Y, Wang J, Chen C, Wu AR. Assessment of microbiota in the gut and upper respiratory tract associated with SARS-CoV-2 infection. Microbiome. 2023 Mar 3;11(1):38. doi: 10.1186/s40168-022-01447-0. PMID: 36869345; PMCID: PMC9982190. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9982190/ (Full text)

The role of the microbiota-gut-brain axis in post-acute COVID syndrome

Abstract:

The COVID-19 pandemic has resulted in the infection of hundreds of millions of individuals over the past three years, coupled with millions of deaths. Along with these more acute impacts of infection, a large subset of patients developed symptoms that collectively comprise “post-acute sequelae of COVID-19” (PASC, also known as long COVID), which can persist for months and maybe even years. In this review, we outline current knowledge on the role of impaired microbiota-gut-brain (MGB) axis signaling in the development of PASC and the potential mechanisms involved, which may lead to better understanding of disease progression and treatment options in the future.

Source: Gareau MG, Barrett KE. The role of the microbiota-gut-brain axis in post-acute COVID syndrome. Am J Physiol Gastrointest Liver Physiol. 2023 Mar 7. doi: 10.1152/ajpgi.00293.2022. Epub ahead of print. PMID: 36880667. https://journals.physiology.org/doi/abs/10.1152/ajpgi.00293.2022 (Full text available as PDF file)

Outpatient Treatment of COVID-19 and the Development of Long COVID Over 10 Months: A Multi-Center, Quadruple-Blind, Parallel Group Randomized Phase 3 Trial

Abstract:

Background: Post-acute sequelae of COVID, termed “Long COVID”, is an emerging chronic illness potentially affecting ~10% of those with COVID-19. We sought to determine if outpatient treatment with metformin, ivermectin, or fluvoxamine could prevent Long COVID.

Methods: COVID-OUT (NCT04510194) was a decentralized, multi-site trial in the United States testing three medications (metformin, ivermectin, fluvoxamine) using a 2×3 parallel treatment factorial randomized assignment to efficiently share placebo controls. Participants, investigators, care providers, and outcomes assessors were masked to randomized treatment assignment. Inclusion criteria included: age 30 to 85 years with overweight or obesity, symptoms <7 days, enrolled within <=3 days of documented SARS-CoV-2 infection. Long COVID diagnosis from a medical provider was a pre-specified secondary outcome assessed by monthly surveys through 300 days after randomization and confirmed in medical records.

Findings: Of 1323 randomized trial participants, 1125 consented for long-term follow up, and 95.1% completed >9 months of follow up. The median age was 45 years (IQR, 37 to 54), and 56% were female (7% pregnant). The median BMI was 30 kg/m2 (IQR, 27 to 34). Overall, 8.4% reported a medical provider diagnosed them with Long COVID; cumulative incidence: 6.3% with metformin and 10.6% with matched placebo. The hazard ratio (HR) for metformin preventing Long COVID was 0.58 (95%CI, 0.38 to 0.88; P=0·009) versus placebo. The metformin effect was consistent across subgroups, including viral variants. When metformin was started within <4 days of symptom onset, the HR for Long COVID was 0.37 (95%CI, 0.15 to 0.95).  No statistical difference in Long COVID occurred in those randomized to either ivermectin (HR=0.99; 95%CI, 0.59 to 1.64) or fluvoxamine (HR=1.36; 95%CI, 0.78 to 2.34).

Interpretations: A 42% relative decrease and 4.3% absolute decrease in the Long COVID incidence occurred in participants who received early outpatient COVID-19 treatment with metformin compared to exact-matching placebo.

Source: Bramante, Carolyn and Buse, John B. and Liebovitz, David and Nicklas, Jacinda and Puskarich, Michael and Cohen, Kenneth R. and Belani, Hrishikesh and Anderson, Blake and Huling, Jared D. and Thompson, Jennifer and Pullen, Matthew and Wirtz, Esteban Lemus and Siegel, Lianne and Proper, Jennifer and Odde, David J. and Klatt, Nichole and Sherwood, Nancy E. and Lindberg, Sarah and Karger, Amy B. and Beckman, Kenneth B. and Erickson, Spencer and Fenno, Sarah and Hartman, Katrina and Rose, Michael and Mehta, Tanvi and Patel, Barkha and Griffiths, Gwendolyn and Bhat, Neeta and Murray, Thomas A. and Boulware, David R., Outpatient Treatment of COVID-19 and the Development of Long COVID Over 10 Months: A Multi-Center, Quadruple-Blind, Parallel Group Randomized Phase 3 Trial. Available at SSRN: https://ssrn.com/abstract=4375620 or http://dx.doi.org/10.2139/ssrn.4375620

Long-term gastrointestinal outcomes of COVID-19

Abstract:

A comprehensive evaluation of the risks and 1-year burdens of gastrointestinal disorders in the post-acute phase of COVID-19 is needed but is not yet available. Here we use the US Department of Veterans Affairs national health care databases to build a cohort of 154,068 people with COVID-19, 5,638,795 contemporary controls, and 5,859,621 historical controls to estimate the risks and 1-year burdens of a set of pre-specified incident gastrointestinal outcomes.

We show that beyond the first 30 days of infection, people with COVID-19 exhibited increased risks and 1-year burdens of incident gastrointestinal disorders spanning several disease categories including motility disorders, acid related disorders (dyspepsia, gastroesophageal reflux disease, peptic ulcer disease), functional intestinal disorders, acute pancreatitis, hepatic and biliary disease.

The risks were evident in people who were not hospitalized during the acute phase of COVID-19 and increased in a graded fashion across the severity spectrum of the acute phase of COVID-19 (non-hospitalized, hospitalized, and admitted to intensive care). The risks were consistent in comparisons including the COVID-19 vs the contemporary control group and COVID-19 vs the historical control group as the referent category.

Altogether, our results show that people with SARS-CoV-2 infection are at increased risk of gastrointestinal disorders in the post-acute phase of COVID-19. Post-covid care should involve attention to gastrointestinal health and disease.

Source: Xu, E., Xie, Y. & Al-Aly, Z. Long-term gastrointestinal outcomes of COVID-19. Nat Commun 14, 983 (2023). https://doi.org/10.1038/s41467-023-36223-7 https://www.nature.com/articles/s41467-023-36223-7 (Full text)

Exogenous Players in Mitochondria-Related CNS Disorders: Viral Pathogens and Unbalanced Microbiota in the Gut-Brain Axis

Abstract:

Billions of years of co-evolution has made mitochondria central to the eukaryotic cell and organism life playing the role of cellular power plants, as indeed they are involved in most, if not all, important regulatory pathways. Neurological disorders depending on impaired mitochondrial function or homeostasis can be caused by the misregulation of “endogenous players”, such as nuclear or cytoplasmic regulators, which have been treated elsewhere. In this review, we focus on how exogenous agents, i.e., viral pathogens, or unbalanced microbiota in the gut-brain axis can also endanger mitochondrial dynamics in the central nervous system (CNS).

Neurotropic viruses such as Herpes, Rabies, West-Nile, and Polioviruses seem to hijack neuronal transport networks, commandeering the proteins that mitochondria typically use to move along neurites. However, several neurological complications are also associated to infections by pandemic viruses, such as Influenza A virus and SARS-CoV-2 coronavirus, representing a relevant risk associated to seasonal flu, coronavirus disease-19 (COVID-19) and “Long-COVID”.

Emerging evidence is depicting the gut microbiota as a source of signals, transmitted via sensory neurons innervating the gut, able to influence brain structure and function, including cognitive functions. Therefore, the direct connection between intestinal microbiota and mitochondrial functions might concur with the onset, progression, and severity of CNS diseases.

Source: Righetto I, Gasparotto M, Casalino L, Vacca M, Filippini F. Exogenous Players in Mitochondria-Related CNS Disorders: Viral Pathogens and Unbalanced Microbiota in the Gut-Brain Axis. Biomolecules. 2023 Jan 13;13(1):169. doi: 10.3390/biom13010169. PMID: 36671555; PMCID: PMC9855674. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9855674/ (Full text)

Predictors of Long-COVID-19 and its Impact on Quality of Life: Longitudinal Analysis at 3, 6 and 9 Months after Discharge from a Portuguese Centre

Abstract:

Introduction: Long-COVID-19 impacts health-related quality of life (HR-QoL) but data is scarce. The aim of this study was to describe and prospectively assess the prevalence and risk factors for long-COVID-19 after hospital discharge, and to evaluate its impact on patient HR-QoL.

Material and methods: Single-centre longitudinal study including all COVID-19 patients discharged between December 2020 and February 2021. Patients were contacted remotely at three, six and nine months. Data were collected as follows: 1) Long-COVID-19 symptoms were self-reported; 2) HRQoL were assessed using the 3-level EuroQoL-5D (EQ-5D-3L) questionnaire. Pregnant women, demented, bedridden, and non-Portuguese-speaking patients were excluded.

Results: The three-, six- and nine-month assessments were completed by 152, 117 and 110 patients (median age: 61 years; male sex: 56.6%). Long-COVID-19 (≥ 1 symptom) was reported by 66.5%, 62.4% and 53.6% of patients and HR-QoL assessment showed impairment of at least some domain in 65.8%, 69.2% and 55.4% of patients at three, six and nine months, respectively. Fatigue was the most common long-COVID-19 symptom. Anxiety/depression domain was the most frequently affected in all three time-points, peaking at six months (39%), followed by pain/discomfort and mobility domains. Long-COVID-19 was associated with the impairment of all EQ-5D-3L domains except for self-care domain at each time-point. Neither intensive care unit admission nor disease severity were associated with long-COVID-19 nor with impairment of any EQ-5D-3L domain. After adjusting for sex, age, frailty status, and comorbid conditions, long-COVID-19 remained significantly associated with HR-QoL impairment at three (OR 4.27, 95% CI 1.92 – 9.52, p < 0.001), six (OR 3.46, 95% CI 1.40 – 8.57, p = 0.007) and nine months (OR 4.13, 95% CI 1.62 – 10.55, p = 0.003) after hospital discharge. In a longitudinal analysis, patients reporting long-COVID-19 at three months had an EQ-5D-3L index value decreased by 0.14 per visit (p < 0.001) compared to those without long-COVID-19 and both groups had a non-significant change in mean EQ-5D-3L index over the nine-month period (time-point assessment, Z = 0.91, p = 0.364).

Conclusion: Clinical sequelae associated with long-COVID-19 can persist for at least nine months after hospital discharge in most patients and can impair long-term HR-QoL in more than half of patients regardless of disease severity, and clinicodemographic characteristics.

Source: Gaspar P, Dias M, Parreira I, Gonçalves HD, Parlato F, Maione V, Atalaia Barbacena H, Carreiro C, Duarte L. Predictors of Long-COVID-19 and its Impact on Quality of Life: Longitudinal Analysis at 3, 6 and 9 Months after Discharge from a Portuguese Centre. Acta Med Port. 2023 Feb 24. doi: 10.20344/amp.19047. Epub ahead of print. PMID: 36827994. https://www.actamedicaportuguesa.com/revista/index.php/amp/article/view/19047 (Full text)